▎ 摘　　要

NOVELTY - Preparation of aqueous polyurethane/graphene nano-composite emulsion, involves (i) preparing graphene oxide dispersion using graphite, potassium permanganate and sodium nitrate concentrated sulfuric acid solution, (ii) adding diisocyanate compound, oligomer polyol and catalyst, reacting, adding hydrophilic monomer, reacting, when determined isocyanate group content of prepolymer approaches theoretical value, reducing temperature, adding hydroxide, reacting, adjusting viscosity, dripping graphene oxide dispersion, mixing, emulsifying, adding reducing agent and reacting. USE - Preparation of aqueous polyurethane/graphene nano-composite emulsion for use in paint, adhesive, ink, surface treatment agent, elastomer, foaming material and functional film applications. ADVANTAGE - The introduction of graphene effectively improves the mechanical properties of aqueous polyurethane film and coating, and also improves antistatic, conductive properties, electromagnetic shielding, thermal conductivity, chemical resistance and corrosion resistance. DETAILED DESCRIPTION - Preparation of aqueous polyurethane/graphene nano-composite emulsion using raw material composition which comprises 30-50 wt.% oligomer polyol, 20-40 wt.% diisocyanate compound, 3-7 wt.% hydrophilic monomer, 2-8 wt.% hydroxide and 0.01-40 wt.% graphene, involves (i) using improved Hummers method to prepare graphene oxide dispersion by adding specific ratio of graphite and potassium permanganate to sodium nitrate concentrated sulfuric acid solution according to certain ratio in the ice water bath conditions, mixing and reacting for 9-12 hours, than slowly adding distilled water, stirring for 1-2 hours, adding 85% of hydrogen peroxide until the mixture becomes pale yellow and does not produce bubbles, centrifuging to wash until the supernatant is neutral, then dialyzing for a week, centrifuging and then dispersing in a mixture of water and dimethylformamide, carrying out dispersion treatment using an ultrasonic cell disintegrator under ice-water bath to obtain graphene oxide dispersion, (ii) adding diisocyanate compound, oligomer polyol and catalyst, reacting at 50 degrees C for 1-2 hours, then gradually heating to 60 degrees C, adding hydrophilic monomer, reacting at 60 degrees C for 6-8 hours, determining isocyanate group content of the prepolymer by toluene-di-n-butylamine method, when the determined isocyanate group content approaches theoretical value, reducing the reaction temperature to 25 degrees C, adding hydroxide, reacting at 60 degrees C for 1-2 hours, then adjusting the appropriate viscosity, dripping graphene oxide dispersion, mixing at high-speed and emulsifying for 1 hours, finally adding reducing agent at 95 degrees C, reacting for 1 hours and obtaining aqueous polyurethane/graphene nano-composite emulsion.